Agents that can kill the viable bacteria, such as antibiotics, can be ineffective to terminate the viability of the bacterial spores, making populations of such bacteria difficult to control. Even if the entire mature population is killed, viable spores are still available for germination to restore a potentially pathogenic bacterial population.
Detecting enzymes, proteins, or chemical agents can be valuable for a wide variety of uses. For example, abnormal formation and deposition of amyloid protein aggregates is associated with a number of neurodegenerative diseases, including, but not limited to, Alzheimer's disease, Parkinson's disease, Huntington's disease, systemic amyloidosis and inherited organ-specific amyloidoses, and transmissible prion diseases such as bovine spongiform encephalopathy, chronic wasting disease, and sheep scrapie. Each of these diseases is characterized by symptoms including cross-β-sheet rich aggregates, formed from characteristic proteins depending upon the specific disease. Understanding, diagnosing, and treating these diseases require tools to locate and track the formation of amyloid aggregates in living organisms, particularly the putative toxic aggregate forms. The primary method for amyloid detection is histopathological staining of tissue sections with fluorescent dyes, of which the commonest currently is Thioflavin T. Existing dyes have limitations; they target primarily mature aggregates and they cannot distinguish between amyloids with differing conformations, particularly oligomeric/pre-fribillar aggregates that are considered the primary toxic species.